Method and apparatus for forming compacted bodies



Sept. 13, 1955 Dj F. DICKEY X 2,717,419

METHOD AND APPARATUS FOR FORMING COMPACTED BODIES Filed Nov. 1, 1952 2 sht s-sheet 1 i i l l l INVENTOR. David E Dickey V @W ATTORNE Y5 D. F. DlCKEY Sept. 13, 1955 METHOD AND APPARATUS FOR FORMING COMPACTED BODIES 2 Sheets-Sheet 2 Filed Nov. 1, 1952 INVENTOR. Dav/d E D/ckey 1" th-v H 5 ATTORNEYS United States Patent METHOD AND APPARATUS FOR FORMING COMPACTED BODIES David F. Dickey, Whitehall, Pa., assignor, by mesne assignments, to Electrolyser Corporation, Ltd., Toronto,

Ontario, Canada, a corporation of Canada Application November 1, 1952, Serial No. 318,298

12 Claims. (Cl; 189) This invention relates to a method and apparatus for forming compacted bodies from a mixture of powder and binder. It is particularly applicable to the treatment of iron powder wherein the iron powder is mixed with a carbonaceous binder and the mixture compacted into compacted bodies such as briquettes. Iron powder itself is readily oxidized and is not in a form suitable for melting in a furnace. It is therefore desirable to compact it into briquettes which can be charged into the melting furnace. Iron powder or briquettes made therefrom without the use of a carbonaceous binder have a relatively high melting point and it is therefore desirable to mix the iron powder with a carbonaceous binder in order that the briquettes made therefrom will have a suitably. low melting point due to the presence of the carbon in the briquettes:

The present invention provides a method and apparatus for intimately mixing iron powder or other powder with a carbonaceous binder and forming compacted bodies from the mixture.

In the accompanying drawings which illustrate two embodiments'of my invention in a diagrammatic manner, V

Figure 1 is a longitudinal section through the whole apparatus;

Figure 2 is a sectional view, on a larger scale, of the forming rolls, illustrating the formation of chains of compacted bodies from the mixture of powder and binder and the severance of the compacted bodies into separate bodies;

Figure 3 is a sectional view of one of the forming rolls and associated parts taken along the line IIIIII of Figure 2; and

Figure 4 is a view similar to Figure 2, but illustrating a different embodiment in which two sets of rolls are employed.

Referring more particularly to the accompanying drawings, and for the present to Figures 1-3, iron powder which may have been produced in a reduction furnace of the type disclosed in my application Serial No. 313,137, filed October 4, 1952, is introduced, while protected from the atmosphere, into a chamber formed by a casing 2. The iron powder is fed from a chute 3 onto a conveyor 4, and as the iron powder passes in the direction indicated by the arrow 5, it is sprayed by sprays 6 with a solution of an organic binder in a suitable low boiling point solvent. Various carbonaceous binders may be employed, as for example pitch, tar or wax. Similarly, various low boiling point solvents may be employed, as for example gasoline, kerosene, hexadecane, propane, pentane or carbon tetrachloride. The iron powder which has been thus treated drops from the end of the conveyor 4 into the bite between a first set of horizontal rolls composed of the rolls 7 and 8. It then passes between a second set of rolls composed of rolls 9 and 10, and then between a third set of rolls composed of the rolls 11 and 12. Each of the rolls is provided with longitudinal grooves 13, as more fully explained later, which compact Z ,7 1 7,419 Patented Sept. 13, 1955 and knead the mixture into compacted bodies or briquettes. The compacted bodies 14 issuing from the last set of rolls drop to the bottom of a chamber 15 in which the various sets of rolls are located and from time to time are discharged from the chamber through a revolving door 16.

Each of the forming rolls is hollow so that steam or other heat means may be fed thereto for heating them to a suitable temperature, and each of the rolls is provided with means for driving it. As shown in Figure '3, the roll 8 is provided with trunnions 17 and 17a mounted in suitable bearings 18 carried by end plates 19. The plates 19 act as end plates for the cylindrical molds formed by the grooves 13 in the rolls. A steam inlet pipe 20 leads to a steam chamber 21 surrounding and rotatably receiving the trunnion 17a. The trunnion 17a is provided with inlet openings 22. A tube 23 provided with inlet openings 23a and outlet openings 23b is located inside the roll 8 and trunnion 17a. The openings 23!) communicate with openings 24 in a steam chamber 25 surrounding and rotatably receiving the trunnion 17a, the chamber 25 being connected to a steam return pipe 26. Thus means is provided for introducing steam into each of the forming rolls. The trunnion 17 is provided with a gear wheel 27 for rotating the roll.

The various sets of forming rolls are heated to a temperature suiiicient to volatilize the solvent but not to volatilize any substantial portion of the binder. That is, where a solution of pitch dissolved in gasoline is employed, the temperature of the rolls is sufficient to volatilize the gasoline but not any substantial portion of the pitch. The volatile solvent passes through a pipe 28 into and through a condenser 29. It then passes through a pipe 30 into a chamber 31 where pitch or other binder is introduced through pipe 32 and additional solvent to make up for that which is lost in the process is added through pipe 33. The solution of binder and solvent are then pumped by pump 34 and pipe 35 back to the sprays 6 for treating a further quantity of powder on the conveyor 4.

Each of the rolls 7-12 is provided with longitudinal grooves 13 around its entire periphery. These grooves are semi-cylindrical so that the cooperating grooves of a set of rolls form substantially cylindrical compacted bodies from the powder. The center distance c between the rolls 7 and 8 is slightly greater than twice the radius a of the rolls so that when iron powder and binder are fed between the bite of the first set of rolls, the rolls compact the powder but do not sever it into individual bodies. The product issuing from the first set of rolls is in the form of a first chain 38 formed of compacted cylindrical bodies 39 connected together along their lengths by narrower rib portions 40 to form the chain.

The chain 38 is then fed between the second set of rolls composed of the rolls 9 and 10. The rolls 9 and 1:) are spaced vertically with respect to the rolls 7 and 8 a distance such that and are so timed that the chain 38 of cylinders 39 in passing between the second set of rolls is re-formed into a new chain 41 of cylinders 42, each new cylinder 42 being composed of one-half of two adjacent cylinders 39 of the first chain 38. The center distance 2 of the rolls 9 and 10. is slightly less than the center distance c of the rolls 7 and 8 in order to provide further compression and compacting of the material as it passes through the second set of rolls. It will be noted, however, that in this embodiment, the center distance e of the second set of rolls is somewhat greater than twice the diameter a of the rolls so that in passing through the second set of rolls, the powder is not severed into separate compacted bodies but still remains in the form of a chain composed of the cylinders 42 joined together by the ribs 43.

The chain 41 formed by the second set of rolls is then fed between a third set of rolls composed of rolls 11 and 12. The rolls 11 and 12 are timed and spaced vertically with respect to the rolls 9 and 10 so that the chain 41 of cylinders 42 is reformed and divided into separate cylinders 14, each cylinder 14 being composed of onehalf of two adjacent cylinders 42. The center distance g of rolls 11 and 12 is such that separate detached cylinders 14 are produced from the chain 41.

In order to further illustrate a working embodiment of the invention, the following dimensions are given for the parts designated in Figure 2, it being understood that the invention is not limited to these dimensions:

In the embodiment shown in Figure 2, each cylinder 42 is composed of one-half of two adjacent cylinders 39 of the first chain 38 and each cylinder 14 is composed of one-half of two adjacent cylinders 42 of the second chain 41. It is not necessary that the subsequent cylinders be composed of equal parts of previously formed cylinders in order to obtain intimate mixing and kneading of the powder, it being sufficient if the subsequent cylinders are formed from substantial portions of previously formed adjacent cylinders.

The compacted bodies such as the bodies 39, 42 and 14 need not be cylindrical but can be of other shapes. Instead of using longitudinal grooves in the rolls, I may use cups which form substantially ball-shaped or other shaped compacted bodies joined together by portions of lesser cross sections to form a chain. Irrespective of the shape of the compacted bodies, any number of sets of rolls may be employed depending upon the requirements of the powder for suitable blending of the binder and density of the compact.

Figure 4 illustrates another embodiment of the invention in which only two sets of rolls are employed. The first set is composed of rolls 45 and 46 and the second set is composed of the rolls 47 and 43. Each of the rolls has longitudinal grooves 49 formed throughout its periphery. The center spacing h of the rolls 45 and 46 is such as to produce a chain 50 of compacted bodies similar to that shown in Figure 2 and composed of cylinders 51 connected by ribs 52. The center spacing i of the second set of rolls 47 and 48 is such as to sever the chain 50 into separate detached cylinders 53, and to further compact the powder in passing through the second set of rolls. Each of the cylinders 53 is composed of one-half of two adjacent cylinders 51 of the chain 50. The embodiment shown in Figure 4 differs essentially from that shown in Figure 2 only in that the intermediate set of rolls is omitted.

The last set of rolls used in carrying out the method could be so spaced and timed with respect to the immediately preceding set of rolls that the last set of rolls merely severs the previously formed chain along the connecting ribs, such as the ribs 43 or 52, without reforming cylinders each composed of portions of two adjacent cylinders of a previously formed chain.

The formation of a chain of cylinders or other shape compacted bodies and the feeding of the chain through a subsequent set or sets of rolls insures intimate mixing and kneading of the binder and powder and the production of homogeneous, strong compacted bodies.

The invention is not limited to the preferred embodiments which have been illustrated and described, but may be otherwise embodied or practiced within the scope of the following claims.

I claim:

1. The method of forming compacted bodies from a mixture of powder and binder, whichcomprises forming from the mixture a plurality of compacted bodies connected by portions of lesser cross section to form a chain, and reforming the chain into compacted bodies each composed of portions of adjacent compacted bodies of the chain.

2. The method of forming compacted bodies from a mixture of powder and binder, which comprises shaping the mixture between a set of forming rolls to produce a chain formed of compacted bodies connected by portions of lesser cross section, and passing the chain between a second set of forming rollslto reform the chain into compacted bodies each composed of portions of adjacent compacted bodies of the chain.

3. The method of forming compacted bodies from a mixture of powder and binder, which comprises forming from the mixture a first chain formed of compacted bodies connected by portions of lesser cross section reforming the first chain into a second chain of compacted bodies each composed of portions of adjacent bodies of the first chain, and reforming the second chain into compacted bodies detached from each other and each composed of portions of adjacent compacted bodies of the second chain. 1

4. The method of forming compacted bodies from a mixture of powder and binder, which comprises forming from the mixture a compacted chain having alternate en-. larged bodies and ribs, and thereafter reformingthe chain into a second chain having alternate enlarged bodies and ribs in which each of the enlarged bodies is composed of portions of adjacent enlarged bodies of the first chain.

5. The method of forming compacted bodies from a mixture of powder and binder, which comprises forming from the mixture a compacted chain having alternate enlarged bodies and ribs, and thereafter reforming and dividing the chain into detached compacted bodies, each composed of portions of adjacent enlarged bodies of the chain.

6. The methd of forming compacted bodies from a mixture of powder and binder, which comprises forming from the mixture a plurality of substantially cylindrical bodies joined together along their lengths by ribs to form a chain of cylindrical bodies, and thereafter reforming the chain to form substantially cylindrical bodies, each composed of portions of adjacent substantially cylindrical bodies of the chain.

7. The method of forming compacted bodies from-a mixture of powder and binder, which comprises compacting the mixture between rotating forming rolls to form a plurality of substantially cylindrical bodies joined together along their lengths by ribs to form a chain of cylindrical bodies, and thereafter further compacting the chainv and changing its shape by passing it through forming rolls-to. form a plurality of substantially cylindrical bodies, each composed of portions of adjacent substantially cylindrical bodies of the chain.

8. A method according to claim 7, wherein the binderis dissolved in a volatile solvent and wherein the solvent is volatilized from the binder during compacting by heat transmitted from the rolls.

9. The method of forming compacted bodies from metal powder, which comprises treating the powder by spraying it with an organic binder dissolved in a volatile solvent having a substantially lower boiling point than the binder, forming the treated powder into a plurality of compacted bodies connected by portions of lesser'cross section to form a chain, subjecting the chain to further compacting and deformation to form compacted bodies, each composed of portions of adjacent compacted bodies of the chain, the compacting being carried out between rotating surfaces, heating the rotating surfaces during compacting to a temperature sufiicient to volatilize the solvent but not the binder, recovering the solvent and using it together with binder for treating a further quantity of powder.

10. Apparatus for forming compacted bodies from a mixture of powder and binder, which comprises a first set of horizontal rolls, a second set of horizontal rolls below and spaced from the first set, each of the rolls being provided with grooves in its periphery, the center spacing cf the first set of rolls being such as to form from the mixture supplied thereto a chain of compacted bodies connected by portions of lesser cross section, and means for rotating the first and second sets of rolls in timed relation to reform the chain into compacted bodies, each composed of pertions of adjacent compacted bodies of the chain.

11. Apparatus according to claim 10, wherein the center spacing of the second set of rolls is less than that of the first set to provide increased compression of the compressed bodies by the second set of rolls.

12. Apparatus for forming compacted bodies from a mixture of powder and binder, which comprises a first set of horizontal rolls, a second set of horizontal rolls below and spaced from the first set, a third set of horizontal rolls below and spaced from the second set, each of the rolls being provided with grooves in its periphery, the center spacing of the first set of rolls being such as to form from the mixture supplied thereto a first chain formed of compacted bodies connected by portions of lesser cross section, means for rotating the first, second and third sets of rolls in timed relation to reform the first chain into a second chain of compacted bodies, each composed of portions of adjacent compacted bodies of the first chain and to reform the second chain into compacted bodies detached from each other and each composed of portions of adjacent compacted bodies of the second chain.

References Cited in the file of this patent UNITED STATES PATENTS 389,117 WillcoX Dec. 9, 1884 1,539,052 McCrohan et al May 26, 1925 2 122,053 Burkhardt June 28, 1938 

10. APPARATUS FOR FORMING COMPACTED BODIES FROM A MIXTURE OF POWDER AND BINDER, WHICH COMPRISES A FIRST SET OF HORIZONTAL ROLLS, A SECOND SET OF HORIZONTAL ROLLS BELOW AND SPACED FROM THE FIRST SET, EACH OF THE ROLLS BEING PROVIDED WITH GROOVES IN ITS PERIPHERY, THE CENTER SPACING OF THE FIRST SET OF ROLLS BEING SUCH AS TO FORM FROM THE MIXTURE SUPPLIED THERETO A CHAIN OF COMPACTED BODIES CONNECTED BY PORTIONS OF LESSER CROSS-SECTION, AND MEANS FOR ROTATING THE FIRST AND SECOND SETS OF ROLLS IN TIMED RELATION TO REFORM THE CHAIN INTO COMPACTED BODIES, EACH COMPOSED OF PORTIONS OF ADJACENT COMPACTED BODIES OF THE CHAIN. 